Autoimmune pancreatitis associated with retroperitoneal fibrosis.

Context: Autoimmune pancreatitis is sometimes associated with other autoimmune diseases. We have presented two cases of autoimmune pancreatitis with retroperitoneal fibrosis and compared our findings with those found in the literature. CASE 1: A 71-year-old male developed anorexia and weight loss. Abdominal ultrasonography (US) and computed tomography (CT) showed diffuse swelling of the pancreas and the peritoneal soft tissue surrounding the aorta, associated with right hydronephrosis. Endoscopic retrograde pancreatography showed narrowing of the main pancreatic duct. He was diagnosed as having autoimmune pancreatitis associated with retroperitoneal fibrosis and underwent steroid therapy. After 3 weeks, a follow-up CT showed a marked reduction in the size of both the pancreas and retroperitoneal mass. CASE 2: A 62-year-old male was admitted to another hospital complaining of obstructive jaundice. Abdominal CT and US showed swelling of the pancreas. Endoscopic retrograde cholangiopancreatography demonstrated stenosis of the lower bile duct and narrowing of the main pancreatic duct. With the diagnosis of pancreatic head carcinoma, a choledochojejunostomy and a gastrojejunostomy were performed. Histological examination of the biopsy of the pancreatic mass revealed marked fibrosis with lymphoplasmacytic infiltration. One year later, a retroperitoneal mass was detected on follow-up CT. He was treated with prednisolone for two years. Recurrence of retroperitoneal mass with left hydronephrosis occurred 18 months later. There was no sign of recurrence of the autoimmune pancreatitis. He was again treated with prednisolone, and the retroperitoneal mass was gradually reduced.

Conclusions: A total of 7 cases including the present cases have been reported. All were middle-aged males. Steroid therapy was effective for both the pancreatic and the retroperitoneal masses.